No they can't "sit"' in water.....your roots will need oxygen and pure water will suffocate them.

Flushing should be a one time thing that you do when your soil chemistry goes out of control so you should water her with several gallons but make sure she has adequate drainage. Iff you need to drill more holes in the bottom of your pot to make sure the water drains out well. No "sitting" in water for any length of time

edit: so perhaps X Factor gave you good advice in the first place....even if for different reasons. Just make sure you have adequate drainage.

Good luck.